Trek's new aero Madone for RadioShack-Nissan

Trek again uses a 90mm-wide bottom bracket shell with bearings that press directly into the frame on the new Madone

(James Huang)

Number holders are built into the custom seatmast caps on RadioShack-Nissan-Trek's new Trek Madones at Critérium du Dauphiné

(James Huang)

The grey paint denotes the truncated sections of RadioShack-Nissan-Trek's new Madone

(James Huang)

RadioShack-Nissan-Trek is racing on a new Trek Madone at the Critérium du Dauphiné

(James Huang)

The roughly straight-bladed fork on the new Trek Madone features a slight cut-out for the front brake

(James Huang)

Trek has carried over some of the Kamm tail truncated airfoil tube shaping philosophy from the Speed Concept to the new Madone

(James Huang)

Trek will again build a tapered head tube into the next-generation Madone but with a presumably more aero shape this time around and a curious stepped interface between the bottom of the head tube and the fork crown. Updated internal cable routing incorporates a barrel adjuster for the rear brake

(James Huang)

The rear brake on the new Trek Madone incorporates a coil spring behind the arm

(James Huang)

Trek couldn't use a standard Shimano Dura-Ace direct-mount rear brake on the new Madone since the housing would be positioned on the wrong side of the bike. Instead, Shimano provides this more complicated setup with a scissor-style link connecting the two arms. Also note the adjustable pivot bearings, which should allow for perfectly slop-free movement

(James Huang)

Trek provide a tidy battery mount positioned below the bottom bracket shell on the new Madone. Unlike the current Madone whose battery is roughly centered on the frame, this one is now offset to help clear the rear brake housing

(James Huang)

We expect the Shimano Dura-Ace direct-mount brake on the new Trek Madone to provide a more positive feel at lever given the very short arms and minimally exposed post mounts on the fork crown

(James Huang)

Trek has moved the rear brake to underneath the chain stays on the new Madone

(James Huang)

Trek looks to have fully embraced Shimano's new Dura-Ace direct-mount brake standard, using it front and rear on the new Madone

(James Huang)

The slim seat stays on the new Trek Madone are now fully separate from end to end, presumably to improve comfort over the current model

Trek's next-generation Madone isn't set for official release for another two weeks but RadioShack-Nissan riders were racing on it at the Critérium du Dauphiné. This new version borrows several key design features from the company's Speed Concept time trial machine, giving the Wisconsin company the aero road bike they’ve been missing for the past few years.

Much like Scott's Foil, the new Madone doesn't actually look all that slippery with its broad tubes and relatively shallow profiles. However, markings on the frame – not to mention strategically applied paint – point to a Kamm tail design with truncated airfoils that are said to mimic the aerodynamic benefits of a much deeper profile without violating UCI technical guidelines or sacrificing chassis weight and ride quality.

Trek have taken the radical step of moving the rear brake down below the chain stays. Just as significant, Trek has wholly adopted Shimano's new direct-mount interface, which does away with the traditional center mounting holes in the frame and fork and replaces them with twin posts on which the newly symmetrical calipers attach directly. In some ways, this is similar to the U-brake posts of old mountain bikes.

In theory, this design could save a few grams by virtue of the omitted caliper parts but the bigger expected benefit is a more direct lever feel and increased power thanks to reduced flex. In addition to locating the caliper arms closer to the base of the frame, the pivots themselves look to be adjustable for play for truly slop-free action.

Another side benefit is the more slender seat stay design. In contrast to the current version's wishbone layout, the new Madone stays are fully separate from dropout to seat tube and there's no bridge whatsoever. These changes could yield a more comfortable ride.

Given the more complicated position, the rear brake is built with a more convoluted X-shaped scissor linkage and the housing runs through the down tube. There's no barrel adjuster built into this end but seeing as how no rider would be able to safely use it anyway Trek has wisely opted to integrated one into the stop on the head tube.

Speaking of routing, Trek maintains fully internal paths throughout but with new easy-to-access ports on the head tube that provide a clea look with optional flush-fit plugs when using electronic transmissions.

Carryover features from the current Madone include a tapered 'e2' head tube, Trek's no-cut seatmast design, a pocket in the chain stay for a Bontrager Duotrap wireless speed and cadence sensor, and a 90mm-wide bottom bracket shell with correspondingly broad down tube and chain stay spacing and direct press-fit bearings.